In recent years, plastics materials as a substitute for metal materials have been actively researched and developed. These materials require various properties depending on their applications. For example, in the case of molded components having a sliding portion such as magnet switches, switch parts or the like among the components of electrical machinery and apparatus, importance is attached to the abrasion resistance and sliding characteristics of the molded components.
On the other hand, moldings of glass fiber reinforced unsaturated polyester resin produced by integrally molding and curing an unsaturated polyester resin, i.e. a typical thermosetting resin, and glass fibers are excellent in impact resistance, tensile strength, bending strength, etc. but have a drawback of poor slidability. Of thermosetting resins, resins such as melamine resins have high surface hardness and great abrasion resistance. However, once a single layer of hard surface has worn off, these resins become unsatisfactory in abrasion resistance like unsaturated polyester resins. Further, said resins are insufficient in lubricity.
The addition of a specific resin has been known as means for improving the abrasion resistance and slidability of thermosetting resins. For example, there have been proposed the addition of polytetrafluoroethylene resin (Teflon) powder (Japanese Unexamined Patent Publication Sho 51-81,852), and the addition of polyethylene (Japanese Unexamined Patent Publications Sho 51-89,546, Sho 51-111,284, Sho 56-74,147 and Sho 58-63,752) and so on.
The addition of asbestos, potassium titanate, wollastonite or the like has been proposed to incorporate fine reinforced fibers as part of a filler. The addition of potassium titanate fibers is known to effectively improve the sliding characteristics and the abrasion resistance (Japanese Unexamined Patent Publications Sho 58-76,413, Sho 59-176,313 and Sho 62-43,454, etc.).
However, these conventional methods failed to give resin compositions which are satisfactory in the excellent sliding characteristics and great abrasion resistance as required when the resin is used as the material for a sliding member.